This invention relates to apparatus for maintaining the integrity of a water trough gas seal and more particularly to apparatus for removing solids from the annular water trough to maintain the water depth in the trough at a desired gas sealing depth and to maintain the heat transfer ability of the water.
The invention is susceptible to application of water sealing means associated with various apparatuses; it will be discussed in connection with an annular cooler chamber associated with a pelletizing system.
In the production of heat hardened pellets of iron-oxide materials, the beneficiated ore concentrate is processed through a kiln system and thereafter cooled so that they may be handled for shipping or storage.
Kiln systems which include straight line coolers have been commercially in use for many years. More recently kiln systems having annular coolers, in which the pellets are cooled in an enclosed circular grate structure wherein the hot gases given off by the pellets are reclaimed and recycled as secondary air within the kiln system, have been introduced and are in demand. In annular coolers the interior of the cooler is at a lower pressure than atmospheric pressure during normal operation. Thus, the ambient atmospheric air is normally urged to enter the enclosure or hood thereby defeating the recycling process.
To overcome this problem, annular channel-shaped water filled sealing means have been developed, as exemplified in U.S. Pat. Nos. 3,460,818 and 3,589,691. In these patents the problem of sediment deposit in the water seal troughs was recognized and an attempt made to minimize such deposits by providing a leveler which traveled with the movable barrier. However, with the arrangement disclosed in the aforementioned patents, periodic shutdown of the kiln system is necessary to remove accumulated sediment deposits or, in lieu of complete cleaning of the troughs, manual syphoning or scooping of the sediment deposits would be attempted. Manual syphoning removes a large amount of water from the trough which is either wasted or requires additional separator equipment and pumps to reclaim the water. Manual syphoning requires that the solids or sediment layer in the water seal trough must be allowed to build up to allow for syphoning. This build-up of solids in the trough reduces heat transfer from the sides of the trough to the water.